The pneumatic powder injection is well-known and widely used with injection lances submerged into metal bath. However, sometimes better is to not introduce the lance below the liquid metal surface because of the metal splashing and introducing of gases into metal volume. In such a case non-submerged lance is used but the problem with particles jet penetration into the metal volume appears. This paper presents the results of the studies on the pneumatic powder injection with non-submerged lance. The high-speed camera recording of the model diphase jet leaving the lance is carried out. Then image analysis is performed to estimate real particles motion parameters. Furthermore, the jet cone is analysed to check its character of development and compared with the reported results in the literature. The results are obtained that the particles real velocity is smaller than calculated from typically used formulas. The same with cone angles - it seems to be different than quoted in the literature. Next stage is numerical modelling using AnSys software. The results were compared with the experiments and the model is adjusted. The next stage is ferroalloy "cold" injection and again the computer modelling. The last stage is FeSi injection into grey iron experiments. The analysis of the results is combined both with the laboratory results and modelling then compared with previous data. As a consequence the validated numerical model is obtained which can be helpful for the injection process planning in industrial conditions.
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The diagnostics of the energy conversion systems' operation is realised as a result of collecting, processing, evaluating and analysing the measurement signals. The result of the analysis is the determination of the process state. It requires a usage of the thermal processes models. Construction of the analytical model with the auxiliary empirical functions built-in brings satisfying results. The paper presents theoretical-empirical model of the steam-water cycle. Worked out mathematical simulation model contains partial models of the turbine, the regenerative heat exchangers and the condenser. Statistical verification of the model is presented.
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The paper presents the application of thermoecological cost methodology as a sustainability measure for biomass co-firing technologies coupled with co-generation of electricity and heat. For both kinds of fuels; fossil fuel (hard coal) and biomass (willow chips) the value of thermoecological cost has been calculated. These parameters have then been used for the evaluation of the thermoecological cost for electricity and heat generated in CHP plant with a backpressure turbine. The change of these values along with the increasing energy share of biomass in the combusted blend has been analyzed. It was observed that biomass addition leads to the decrease of the thermoecological cost of electricity and heat generated in co-firing processes.
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The paper discusses chosen issues concerning damaged gas pipelines. Attention is paid to modelling the steady-state flow of natural gas in distribution pipelines, and the most commonly applied models of isothermal and adiabatic flow are evaluated for both the ideal and the real gas properties. A method of accounting for a leakage by means of a reference flow equation with a discharge coefficient is presented, and the dependency of the discharge coefficient on pressure is demonstrated both with literature data and the authors' experimental results. A relevant computational study of a pipeline failure is presented for a high-and a medium pressure pipeline. The importance of an appropriate choice of the flow model (isothermal or adiabatic flow of real or ideal gas) is demonstrated by the results of the study. It is shown that accounting for the variability of the discharge coefficient is required if medium pressure pipelines are analyzed. However, it is eventually shown that the impact of the discharge coefficient on the predicted outflow rate is of lesser importance than that of the applied flow model.
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The subject of this paper is a development of a rapid, in-situ method of retrieving the orthotropic heat conductivity. The technique can be seen as an enhancement of the known Parkers flash technique [1]. The presented technique is capable of handling orthotropic media of arbitrary shape, provided the measurement surface is planar and two principal axes of the heat conductivity tensor are in that plane. The need for determining anisotropic conductivity arises when dealing with a certain type of crystalline materials like carbon but also when evaluating the equivalent conductivity of composites. The proposed method uses an infrared camera to record the variation of the temperature field induced by a laser impulse. Both the camera and the laser are located on the same side of the body under investigation.
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